Tysabri natalizumab: Post-marketing study data

As of Sept. 2, Biogen Idec said that there have been 68 confirmed cases of progressive multifocal leukoencephalopathy (PML) in patients receiving Tysabri monotherapy for MS since the drug was relaunched in the U.S. and its first international approval in 2006. As of June 30, Biogen Idec reported that approximately 71,400 patients have been treated with Tysabri in the post-marketing setting. ...